Food Packages and Methods of Manufacture

ABSTRACT

A package is disclosed for containing a plurality of individual food items within a tray having an outer surrounding wrapper. The tray is configured to have enhanced rigidity in a longitudinal direction to accommodate greater applications of pressure when forming envelope seals of the outer surrounding wrapper adjacent ends of the tray.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No. 11/925,335 filed Oct. 26, 2007, which is hereby incorporated by reference in its entirety.

FIELD

This disclosure relates generally to food packages and methods of manufacture, and in particular to trays for containing food products and enclosed with an outer surrounding wrapper.

BACKGROUND

Food packages may be in the form of a tray containing multiple food items, which may in turn be individually wrapped. An outer film wrapper can surround the tray to enclose the multiple food items in the tray. One type of such tray is known as a “Brightwood” tray. Such trays are typically formed of paperboard and have a transparent outer film wrapper. The outer film wrapper maintains the food items in the tray during shipping and handling. The food packages may be sold to consumers in their entirety. Alternatively, the outer film wrapper can be removed and the food items removed therefrom for sale to consumers. In yet another alternative use, the outer film wrapper can be removed and the tray used for storage of the food items until removed for use or for sale to consumers. Such trays are designed to be inexpensive, in part because they may or may not be used after shipping.

An example of a prior art “Brightwood” tray is illustrated in FIG. 3. A disadvantage of this type of tray is that it lacks rigidity in a longitudinal direction, i.e., parallel to the longest dimension of the tray. When stacked with other trays or other items on top, the longitudinal side walls can buckle, as illustrated in FIG. 3. This and other such handling can result in a deformed package, unattractive in appearance.

When the outer film wrapper is placed around the prior art “Brightwood” tray, fin seals, spaced from the tray, can be formed at each end. Such fin seals can disadvantageously result in an outer wrapper that is loosely fitting around the tray, which can have an undesirable appearance. In addition, the fin seals can hinder the package from being stood on the ends having the end seals.

To get a more closely fitting outer wrapper and to have the package be able to stand on its ends having the seals of the outer wrapper, envelope seals can be formed in the outer wrapper adjacent to each end of tray. The strength of the envelope seals is a function of pressure, dwell time for heating bars, and the temperature of the heating bars. Due to the lack of rigidity in the longitudinal direction, however, the strength of the envelope seals is limited in part by the amount of pressure that can be applied. This can in turn require a greater dwell time and/or increased temperature application. A greater dwell time of the sealing bars disadvantageously can cause increased production time of the food packages.

SUMMARY

A package is disclosed for containing a plurality of individual food items within a tray having an outer surrounding wrapper. The tray is configured to have enhanced rigidity in a longitudinal direction in order to increase packaging speeds. In particular, the tray may be configured to accommodate greater applications of pressure when forming envelope seals of the outer surrounding wrapper adjacent ends of the tray. The greater application of pressure beneficially can result in an envelope seal that requires less sealing time, thereby permitting increased packaging speeds for the forming, filling and sealing of the packages. Another benefit of the enhanced rigidity of the tray can be greater durability during shipping and handling.

The tray may have a generally rectangular rear wall with a pair of longitudinal side edges and a pair of transverse side edges, a pair of longitudinal side panels attached to the longitudinal side edges of the rear wall, a pair of transverse side panels attached to the transverse side edges of the rear wall, and a minor flap attached to each of the longitudinal side panels along an edge thereof opposite the longitudinal side edges of the rear wall. At the intersections of the minor flaps and the longitudinal side panels is a fold line. This fold line can provide additional rigidity to the tray in a longitudinal direction.

To take advantage of the increased rigidity in the longitudinal direction, the envelope seals in the outer wrapper are formed adjacent to each of the transverse side panels to enclose the tray. During formation of the envelope seals, sealing bars apply pressure to the film overlying the transverse side panels to seal the film to itself. Because the seal strength is a function of pressure, dwell time, and sealing bar temperature, the increased rigidity permits the tray to withstand increased compressive forces applied at each end, which can advantageously lead to decreased dwell time and thus increased packaging speeds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tray for a food package;

FIG. 2 is a perspective view of the tray of FIG. 1 with an outer surrounding wrapper and containing individually-wrapped food items;

FIG. 3 is a perspective view of a prior art tray having an outer surrounding wrapper and containing individually-wrapped food items;

FIG. 4 is a plan view of a blank for use in forming the tray of FIG. 1;

FIG. 5 is an illustrative perspective view of the blank of FIG. 4 being folded to partially form the tray of FIG. 1;

FIG. 6 is an illustrative perspective view of the partially formed tray of FIG. 1;

FIG. 7 is an illustrative perspective view of minor flaps being folded to form the tray of FIG. 1;

FIG. 8 is an illustrative perspective view of the tray of FIG. 1 being filled with individually-wrapped food items;

FIG. 9 is an illustrative perspective view of the tray and individually-wrapped food items of FIG. 8 being placed in a film sleeve; and

FIG. 10 is an illustrative perspective view of the sleeve of FIG. 9 being formed with envelope seals at each end of the tray.

DETAILED DESCRIPTION OF THE DRAWINGS

A food package 10 is disclosed herein and illustrated in FIGS. 1, 2 and 4-10 for containing a plurality of individual food items 8 within a tray 30 having an outer surrounding wrapper 12. The tray 30 is configured to have enhanced rigidity in a longitudinal direction, which in turn permits greater pressure to be applied to the tray when forming envelope seals 20 at each end of the package 10. The application of greater pressure can lead to decreased dwell time for forming the envelope seals 20, thereby increasing packaging speeds. The tray 30 may contain individually wrapped food items 8, or unwrapped food items.

The tray 30 has a generally rectangular rear wall 32 with a pair of longitudinal side edges 42 and a pair of transverse side edges 44, as illustrated in FIG. 4. A pair of longitudinal side panels 36 are attached to the longitudinal side edges 42 of the rear wall 32. A pair of transverse side panels 34 are attached to the transverse side edges 44 of the rear wall 32. In order to provide additional rigidity in the longitudinal direction, a minor flap 38 is attached to each of the longitudinal side panels 36 along an edge 46 thereof, opposite the longitudinal side edges 42 of the rear wall 32. The minor flaps 38 provide additional rigidity to the package 10 by virtue of the fold line 46 between each of the minor flaps 38 and their associated longitudinal side panels 36. Minor panels 40 are attached to each side edge 48 of the longitudinal side panels 36, and can be adhesively attached to the adjacent transverse side panels 34 when the tray 30 is assembled, as illustrated in FIGS. 1 and 2.

Although the longitudinal side panels 36 are depicted as being longer than the transverse side panels 34, the opposite may also be true. The terms longitudinal and transverse as used herein are for description only, and are not limiting in terms of their relative dimensions. Enhanced rigidity can also be accomplished by having one or more fold lines formed in the longitudinal side panels 36 in a direction generally parallel to the length direction of the panels 36. For example, three fold lines can be formed in each fo the panels 36 to form a compressed V-shaped protuberance, which can be external or internal.

When the tray 30 is configured from the blank 50, shown in FIG. 4, to fully assembled, shown in FIGS. 1 and 2, the transverse side panels 34 and longitudinal side panels 36 are orientated generally perpendicular to the rear wall 32. In particular, the transverse side panels 34 are folded about fold lines or edges 44 relative to the rear wall 32 and the longitudinal side panels 36 are folded about fold lines or edges 42 relative to the rear wall 32. The fold lines may be prescored, perforated or otherwise weakened to facilitate folding and assembly of the tray 30. To secure the longitudinal side panels 36 relative to the transverse side panels 34 and the rear wall 32, the minor panels 40 are folded inwardly and adhesively attached to the transverse side panels 34. Alternatively, the minor panels 40 may be provided on the transverse side panels 34 and adhesively attached to the longitudinal side panels 36. In either configuration, however, the minor panels 40 may not be adhesively attached. Tabs and slots or the like can be used to secure the minor panels 40, or they simply may be left unattached.

Turning to more of the details of the minor flaps 38, they are illustrated as extending the entire length of the longitudinal side panels 36. This advantageously provides close to the maximum amount of fold line 46, and thus the maximum amount of increased rigidity therefrom. However, the minor flaps 38 may extend only substantially the entire length of the longitudinal side panels 36, or even less than substantially the entire length. In addition, the minor flaps 38 may be divided into multiple segments. The minor flaps 38 preferably, though not necessarily, are unattached at their ends. As it is primarily the fold lines 46 between the minor flaps 38 and the longitudinal side panels 36 that provide increased rigidity to the package 10, the minor flaps 38 do not need a large width. Indeed, the width can be minimized in order to reduce the amount of material, and thus the cost, of the tray 30. In the illustrated example, the ratio of the width of the minor flaps 38 is between about 5% and 15% of the width of the tray 30. Reduced-width minor flaps 38 can also be desirable by permitting a large opening through which the food items 8 can be inserted, viewed and removed. However, in addition to the strength added by the fold lines 46, the minor flaps 38 can themselves act as columns to provide further strength, particularly when they extend at least substantially the length of the longitudinal side panels 36.

The outer film wrapper 12 encloses the tray 30, such as when filled with food items as illustrated in FIG. 2. The outer film wrapper 12 has a longitudinal seam 22 extending generally parallel to the length of the longitudinal side panels 36. At each end of the tray 30, envelope seals 20 are formed in the outer film wrapper 12, as illustrated in FIG. 2. The envelope seals 20 have a first flap 16 overlying a second flap 14, with a heat seal 18 being formed in the area of overlap. The envelope seals 20 are adjacent to and overlie the transverse side panels 34. During formation of the envelope seals 20, increased pressure can be applied at each end of the tray 30 due to the additional rigidity in the longitudinal direction provided by the folds 46 between the longitudinal side panels 36 and the minor flaps 38. As discussed above, application of increased pressure can reduce the time necessary to form the envelope seals 20, thereby permitting for increased speeds of forming, filling and wrapping the trays 30. The increased rigidity can reduce buckling of the longitudinal side panels 36 during formation of the envelope seals 20, as in the prior art package illustrated in FIG. 3.

In one example, the tray 30 is formed of paperboard and the film 12 is transparent. The tray 30 may have a width of between about 5.5 and 6.5 inches, a depth of between about 3 and 4 inches, and a height of between about 9 and 11 inches. The widths of the minor flaps 38 can be between about 0.25 and 0.75 inches. These dimensions are given by way of example only, and other dimensions can be equally suitable.

One exemplary method of forming the package 10 is illustrated in FIGS. 5-10, with arrows indicating the machine flow direction. The first step is to form the blank 50, illustrated in FIG. 4, into a partially formed tray 30, as illustrated in FIG. 5. A ram may be used to force the blank 50 through the chute. This can be accomplished using a folding chute or the like. Adhesive, such as hot melt glue, may be preapplied to the minor panels 40 or the adjacent transverse side panels 34 to secure the minor panels 40 thereto. In the partially formed stage, illustrated in FIG. 6, the minor flaps 38 are not yet folded inward. At this stage, the food items 8 may be placed into the tray with minimal interference from the minor flaps 38. However, the food items 8 may also be placed into the tray 30 at a later stage, illustrated in FIG. 8, after the minor flaps 38 have been folded. The partially formed tray 30 can be advanced in the machine direction and folding rails can be utilized to fold the minor flaps 38 relative to the longitudinal side panels 36, as illustrated in FIG. 7. After being fully formed and filled with the food items 8, the outer film wrapper 12 is formed into a sleeve 24, illustrated in FIG. 9, around the tray 30. In particular, a forming horn or the like can be used to wrap the film 12 around the tray 30 as the tray 30 advances in the machine direction. Alternatively, the film 12 can be cut into the preferred length and wrapped around each tray 30, such as while the tray 30 is paused from advancing in the machine direction. The film 12 is sealed to itself along longitudinal side edge portions thereof using a sealing bar in order to form the sleeve 24 around the tray 30. The sleeve 24 surrounding the tray 30 can then be singulated, if not already separated as in the alternative wrapping method discussed above, from the remainder of the film 12 and the envelope seals 20 formed at each end of the tray 30, adjacent the transverse side panels 34. As illustrated in FIG. 10, heated sealing bars 52 can generally simultaneously apply compressive pressure at each end of the tray 30 to form the envelope seals 20. As discussed above, the increased rigidity of the tray 30 in the longitudinal direction advantageously can permit for increased compressive pressure to be applied by the sealing bars 52, thereby reducing the dwell time required for forming the envelope seals 20 as compared to similarly heated sealing bars used in prior art packages of the type illustrated in FIG. 3.

From the foregoing, it will be appreciated that food packages and methods of assembly and use thereof are provided that have increased rigidity in a longitudinal direction. However, the disclosure is not limited to the aspects and embodiments described hereinabove, or to any particular embodiments. 

1. A method of enclosing a tray in a film wrap, wherein the tray has a generally rectangular rear wall with a pair of longitudinal side edges and a pair of transverse side edges, a pair of longitudinal side panels attached to the longitudinal side edges of the rear wall, a pair of transverse side panels attached to the transverse side edges of the rear wall, and a minor flap attached to each of the longitudinal side panels along an edge thereof opposite the longitudinal side edges of the rear wall, the method comprising: sealing longitudinal edges of a film to form a sleeve; placing the tray in the sleeve with the longitudinal edges of the film being generally parallel to the longitudinal side edges of the rear wall; and forming an envelope seal at each open end of the sleeve and adjacent each of the transverse side panels to enclose the tray in the film wrap.
 2. The method of claim 1, wherein forming the envelope seals further includes applying pressure and heat against overlapping portions of the sleeve with the transverse side panels therebeneath.
 3. The method of claim 2, wherein forming the envelope seals further includes forming both envelope seals at substantially the same time.
 4. The method of claim 3, wherein forming the envelope seals at substantially the same time includes applying compressive pressure against each of the transverse side panels and at least partially countering the compressive pressure via the longitudinal side panels and the minor flaps.
 5. The method of claim 4, wherein the minor flaps extend substantially along the length of the longitudinal side panels.
 6. The method of claim 1, further comprising: providing a blank for forming the tray, the blank being prescored along fold lines between the back panel and the longitudinal side panels, between the back panel and the transverse side panel, and between the longitudinal side panels and the minor flaps; and folding the blank along the fold lines for forming the tray.
 7. The method of claim 6, further comprising inserting individually-wrapped food packages into the tray after folding the blank and prior to placing the tray in the sleeve.
 8. A method of enclosing a tray in a film wrap, wherein the tray has a generally rectangular rear wall with a pair of longitudinal side edges and a pair of transverse side edges, a pair of longitudinal side panels attached to the longitudinal side edges of the rear wall, a pair of transverse side panels attached to the transverse side edges of the rear wall, and a minor flap attached to each of the longitudinal side panels along a fold line extending substantially parallel to an associated longitudinal side edge of the rear wall, the method comprising: folding the minor flaps inward from the longitudinal side panels such that the minor flaps extend over the rear wall; applying a film wrap to the tray; and forming an envelope seal of the film wrap adjacent each of the transverse side panels to enclose the tray in the film wrap.
 9. The method of claim 8, wherein forming an envelope seal adjacent each of the transverse side panels comprises applying compressive pressure against the transverse side panels and transmitting a portion of the compressive force along the fold lines between the minor flaps and the longitudinal side panels.
 10. The method of claim 9, wherein forming the envelope seals further includes forming both envelope seals at substantially the same time.
 11. The method of claim 8, further comprising inserting food packages into the tray after folding the minor flaps inward.
 12. The method of claim 8, wherein applying a film wrap to the tray includes sealing longitudinal edges of the film wrap to form a sleeve; and placing the tray in the sleeve with the longitudinal edges of the film being generally parallel to the longitudinal edges of the rear wall.
 13. A method of forming a package, the method comprising: folding a pair of longitudinal side panels and a pair of transverse side panels of a carton blank into a generally perpendicular orientation relative to a rear wall of the carton blank; securing the longitudinal side panels and the transverse side panels in the generally perpendicular orientation to form a tray; folding minor flaps attached to the longitudinal side panels inwardly towards one another about fold lines extending between each of the minor flaps and an associated longitudinal side panel, wherein each fold line extends substantially parallel to an associated longitudinal side edge of the rear wall spaced from the fold line by the associated longitudinal side panel; surrounding the tray with a film wrap to enclose the tray and to restrict movement of the minor flaps away from the rear wall; and forming envelope seals in the film wrap adjacent each of the transverse side panels.
 14. The method of claim 13, wherein forming an envelope seal adjacent each of the transverse side panels comprises applying compressive pressure against the transverse side panels and transmitting a portion of the compressive force along the fold lines extending between each minor flap and the associated longitudinal side panel.
 15. The method of claim 13, wherein folding minor flaps attached to the longitudinal side panels includes folding multiple segments of each minor flap.
 16. The method of claim 13, wherein surrounding the tray with the film wrap includes: sealing longitudinal edges of the film wrap to form a sleeve; and placing the tray in the sleeve with the longitudinal edges of the film being generally parallel to the longitudinal side panels of the tray.
 17. The method of claim 13, wherein forming envelope seals in the film wrap includes applying pressure and heat against overlapping portions of the film wrap with the transverse side panels therebeneath.
 18. The method of claim 13, wherein securing the longitudinal side panels and the transverse side panels in the generally perpendicular orientation includes adhesively attaching each of the transverse side panels to a pair of minor panels of the longitudinal side panels.
 19. The method of claim 13, wherein each minor flap extends substantially the whole length of the associated longitudinal side panel.
 20. The method of claim 13, wherein the minor flaps do not overlap with each other. 